Fractionation of tall oil



Nov. 211, 1950 FRACTIONATION OF TALL OIL Filed Aug. 23, 1949 NAPHTHA & TALL OIL 5 Sheets-Sheet 1 F H G i UNSAPTNIFIABLES IE IS 5 b 3 C f SOLIDS? FROM l WATER 1/ NAPHTHA 8c TALL OIL SAPONIFICATION UNSAPONIFIABLES OF TALL OIL & LOWER ALCOHOL & warm I II P 53 5? 3 2 q? 3 B u E 85 OE NAPHIHAI T T I w A.

TALL OIL SOAPS 5c LOWER ALCOHOL & WASH WATER & TRACES OF WATER l4- TALL OIL SOAPS V Y STILL SOLVENT s0APs ACID- ACID {PIER STOR- AGE 10 INVENTORS ROGER M. CHRlSTENSON "w By STEWART W. GLOYER @QMF/ZLL ATTU/QNEY Nov, 21, 1950 R. M. CHRISTENSON ET AL 2,530,809

FRACTIONATION OF TALL OIL Filed Aug. 25, 1949 5 Sheets-Sheet 2 FEQZ SAPONIFIED TALL OIL SEPARATION IN THE SYSTEM SAPONIFIED TALL oIL ISOPROPANOLQWATER-B NAPHTHA AT 80F ISOPROPANOL AREA OF FAIR/ AREA OF GOOD WATER SEPARATION SEPARATIOI W YYY A/VVW INVENTORS 4 ROGER m. CHRISTENSON STEWART w. aLoYm NV 211, 1950 R. M. CHRISTENSON ET AL 9 3 FRACTIONATION 0F TALL OIL Filed Aug. 23, 1949 5 Sheets-Sheet 5 FEG.

SAPONIFIED TALL OIL SEPARATION OF THE SYSTEM SAPONIFIED TALL OIL ISOPROPANOL WATER-*NAPHTHA AT 120 F AREA OF POOR SEPARATION v A [\A 1 XXV ISOPROPANOL AREA OF GOOD SEEARATION WATER AREA OF FA IR SEPARA [ION INVENTORS q ROGER mcnms'rewsow '0 BYSTEWAQT w. GLOYER.

NW0 9 3195 R. M. CHRISTENSON ET AL ,8@

FRACTIONATION 0F TALL OIL Filed Aug. 23, 1949 5 Sheets-Sheet 4 SAPONIFIED TALL OIL SEPARATION IN THE SYSTEM SAPONIFIED TALL OIL mm METHANOL-NAPHTHA AT 80F,

ME'I'HANOL AREA OF GOOD SEPARATION WATER INVENTORS ROGGR m. CHRISTENSON B1TEWAIZT w. GLOYER.

NW0 211, 19540 R. M. CHRISTENSON ET AL FRACTIONATION OF TALL OIL Filed Aug. 25, 1949 5 Sheets-Sheet 5 SEPARATION OF THE SYSTEM SAPONIFIED TALL OIL SAPONIFIED TALL OIL METHANOL WATER NAPHTHA AT 135%.

METHANOL AREA OF POOR SEPARATION AREA OF GOOD SEPARATION WATER INVENTORS ROGER M. CHRISTENSON 5 0 STEWART W. GLOYER.

ATM)

i a tented Nov. 21, 1956 Rdger Christensen and Stewart W. Gloyer', Milwaukee, Wis assignors to Pittsburgh Plate Glass Company Appiication August 23, 1949, Serial No. 111,804

6 Claims.

The present invention relates to the treatment of the residues or by-products from the manufacture of paper pulp and it has particular relation to the treatment of the residues or byproducts known as tall oil soaps obtained in the waste liquors from the digestion of pine wood in order chemically to convert it into paper pulp.

One object of the invention is to recover sterols from the by-products above indicated in a form suitable for use in the preparation of sex hormones, wetting agents and other valuable products.

A second object is to increase the yield of valuable disti ed fatty acids and rosin acids recoverable from tall oil or tall oil soaps.

A third object is to provide rosin acids and and fatty acids having improved drying characteristics when incorporated into paint compositions.

A fourth object is to provide a process of obtaining the sterols and other useful components of tall oil in which the unsaponfiable matter containing the sterols is extracted directly by counter-current methods from the crude paste of soaps of tall oil acids and unsaponifiable matter Q as obtained in the paper industry.

ihese and other objects of the invention will be apparent from consideration of the following specification and the appended drawings.

In the drawings, Figure, l diagrammatically illustrates an embodiment of apparatus suitable for use in the practice of the invention.

Figure 2 is a graph showing by triangular coordinates the approximate limits at a lower temperature of the operable syst ms of tall oil solids, water and isopropyl alcohol.

Figure 3 is a similar curve for a higher operating temperature.

Figures 4 and 5 are graphs corresponding respectively to Figures 2 and 3 but applying to the use of methanol as the alcoholic medium.

In the practice of the invention the following steps are employed:

Firstly, the crude by-product or residue from the manufacture of paper pulp known as the soaps of tall oil are admixed with a lower alcohol preferably of the monohydric alkanol type and water to obtain a solution of the tall oil soaps and the unsaponifiable matter associated therewith.

Secondly, the soap solution is subjected to extraction with a solvent which is immiscible in, or but partially miscible with the soap solutions and which is a solvent for the unsaponifiable constituents of the tall oil. Solvents for the unsaponifiable matter appropriate for the purpose include naphthas and other material which will be referred to in greater detail subsequently. The extraction of the soap solution with the solvent for the unsaponifiable matter may be conducted batchwise, but preferably it is conducted countercurrently in a packed column, although an unpacked column of suitable design, or other contacting device could also be employed.

-'Ihirdly, the solution of unsaponifiable material extracted from the soap solutions is washed with water to free it of any traces of soaps of tall oil carried over therein.

Fourthly, the washed solution of unsaponifiable material rich in sterols, coloring matter and any other unsaponifiable constituents is subjected to evaporation and stripping in order to eliminate the solvent.

Fifthly, the crude unsaponifiable material rich in sterols is dissolved in an appropriate solvent such as one of the lower alcohols or acetone and subjected to crystallization in order to obtain the sterols in relatively pure form.

Sixthly, if desired, the soaps of fatty acids and rosin acids in the water-alcohol solution may be recovered in any convenient manner. One such method of recovery would involve precipitation or salting out. Another convenient method would involve evaporation of the alcohol.

The soaps may then be treated with acid such as hydrochloric acid, sulfuric acid or other strong soluble acid designed to liberate the free fatty acids and free rosin acids. The free acids sub sequently are washed with water to remove salts and any residual mineral acids contained therein. The mixture of acids may then be distilled under vacuum and obtained in a state of exceptional value for industrial application.

In Figure 1 is diagrammatically shown an embodiment of apparatus adapted for the counter, current fractionation of the tall oil soaps.

The apparatus comprises columns I and II, the first of which is employed for extracting the unsaponifiable matter by means of a solvent rela-' tively immiscible with the soap solutions and the second of which is employed in the operation of washing the solution of unsaponifiable matter in order to remove traces of soaps. In the practice of the invention a solution of the crude byproduct termed tall oil soaps, made up prefer ably in water and a lower alcohol in a manner hereinafter described, is fed in to the column I near the top thereof as indicated at 3 and a solvent of the unsaponifiable matter relatively immiscible vith the water and alcohol is fed in near the bottom as indicated at A naphtha such as a heptane fraction from an aliphatic petroleum hydrocarbon constitutes a good solvent for the unsaponifiable material. It will be appreciated that if the solvent :or unsaponifiable material is of greater density than the soap solutions, it may be fed in at the top of the column I mine the soap solutions are fed in at the bottom.

The aqueous alcohol solution of soaps flows as a liquid through the column countercurrently with respect to the solvent for the unsaponifiable matter and is drawn on"- from clearing zone a. at the bottom of the column (assuming the soap solution be of the greater density) as indicated at 5. The feed rate is dependent upon the size of the column, the nature of packing and such like factors, but should not be so great as to cause mechanically entrained solvent of unsaponifiable matter to pass out of the column along with the aqueous alcohol or vice versa. This condition is easily observed. Very slow feeds are objectionable because of unnecessarily low output but otherwise are permissible. The soap solution passes to a still 6 for the removal of solvents contained therein. The mixture of soaps from which the solvents have been evaporated pass through a line 'I to a container 8 where they are acidified in order to regenerate the free acids such as rosin acids and fatty acids. The free rosin and fatty acids pass out from the acidificr through a line 9 to a container in which may be employed for purposes of storage pending use or shipment of the material, or further treatment thereof. Such further treatment may, for example, comprise water washing in order to remove salts and other water soluble substances admixed with the free fatty acids and free rosin acids. tilled preferably under vacuum, 6. g. vacuum of the order of 0.5 to 50 millimeters pressure. In this manner acids of high merit in the manufacture of (mating composition, paints, and soaps are recovered. Only a small still residue remains after the distillation operation.

The solution of unsaponifiable matter in naphtha or other appropriate solvent immiscible with aqueous alcohol soap solution is drawn off at the top of column I from clearing zone I) through line H.

For purposes of washing the solution to free it of residual soaps, the solution is passed to column II at a point slightly above the bottom. Simultaneously, Wash water is fed into the column as indicated at I2 slightly below the top and flows counter-currently through the solution of unsaponifiable matter. The latter solution is drawn off through line l3 at the top of column 11. Simultaneously, water containing residual soaps and other water soluble constituents is drawn off as indicated at 14 and may be subjected to further treatment, e. g. to acidification to precipitate free rosin and fatty acids or it may be discharged as waste or dissolved alcohol may be recovered by distillation. Clearing zones and d are provided respectively at the top and bottom of column II.

The naphtha solution of unsaponifiable matter containing a high percentage of sterols may also be subjected to further treatment. For example, the naphtha may be evaporated. The sterols may then be crystallized out of a solvent such as methyl alcohol, ethyl alcohol, acetone, or other appropriate solvent or solvent mixture Subsequently, the acids are disand are obtained in a state of exceptional purity in which they are excellently adapted for use in the synthesis of pharmaceuticals, emulsifiers, anti-oxidants, and other products.

It will be appreciated that in the preparation of water-alcohol solutions of the crude soaps and unsaponifiable matter of tall oil, various alcohols may be employed. These include methyl alcohol, ethyl alcohol, normal propyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol, and other alcohols notably of the alkanol type which are water soluble, at least to a reasonable degree. Methanol, ethanol and isopropyl alcohol are especially suitable. Solutions may be made up to approximately the following composition:

Crude soaps of tall oil, 5 to 35% and preferably Water soluble alcohol, e. g. isopropyl alcohol,

15-50 (preferably 16-27 Water, the rest of the composition.

Any solvents for the unsaponifiable matter in tall oil and which are immiscible with or only partially miscible with the water-alcohol solutions may be employed to extract the unsaponifiable matter. In this group may be included the various alkanes such as the heptanes, or the other petroleum fractions which are not excessively volatile or which are not of such high boiling point as to be diflicult to remove from the unsaponifiable matter by evaporation. Ethers, such as diethyl ether, methyl ethyl ether, isopropyl ether, ethyl or methyl isopropyl mixed ethers, aromatic hydrocarbons such as benzene, toluene or xylene, or chlorinated hydrocarbons such as ethylene dichloride, and others may be employed in the separation of the unsaponifiable matter from the soap solutions. It is usually preferred to employ the solvent for unsaponifiable matter in a ratio of about 1 to l with respect to the soap solution. However, this ratio may be much higher, for example 15 or 20 parts by volume per part of soap solution. Lower ratios are also contemplated. A good working range for naphtha as the solvent of unsaponifiable matter would be .5 to 10 parts by volume of naphtha per part of soap solution subjected to extraction. Excessive increase of the ratio of solvent for the unsaponifiable material tends to become uneconomical because of the large volumes of solvent which must be handled and the cost of evaporation. The following examples illustrate the practice of the invention:

Example I In this example, isopropyl alcohol was employed with water as the solvent medium. A tall oil soap obtained by evaporating a part of the liquids from the crude product as obtained from the paper making industry and containing about 60 per cent of solids including about per cent of soaps of rosin and fatty acids, was employed. No additional alkali was required. This material was of pasty consistency and contained unsaponifiable matter within a range of 4.8 to 6 per cent of the paste composition.

In order to prepare an extractable solution, 40 parts by weight of the paste containing 24 parts of solids and 16 parts of water were dissolved in 56 parts of water and 64 parts of isopropyl alcohol. This solution was then subjected to countercurrent extraction with a heptane fraction of petroleum hydrocarbon in column I. The soap solution was fed into the column through line 3 v and naphtha was fed in as indicated at 4, the feed ratiosbeing 40 parts by volume of the solution of crude tall oil soaps to 80 parts by volume of the heptane fraction. The heptane solution was drawn ofi at 11 and the solution of soaps in water and isopropyl alcohol was drawn oil at. The temperature of operation was about 75 t'o'80 F. but could have been higher or lower. In order to obtain thorough extraction, the soap solution could be passed several times through the same column or could be passed through a succession of columns operated in a series where it could be washed repeatedly with naphtha or other solvent for unsaponifiable matter.

The naphtha extract containing the unsaponifiable material from the crude tall oil soaps was subsequently washed free of soaps and alcohol and other water soluble constitutent in column 11. The washing operation was conductedas follows:

Feed of naphtha containing unsaponifiable material, 80 arts by volume;

Water feed 240 parts by volume;

Temperature of washing approximately 130 to 150 F.

Other temperatures of washing could be employed, if so desired. The rate of feed is regulated to obtain satisfactory phase separation which, of course, is a function of the packingand of the size of the column at a given rate of feed and is readily determined by observing the output of the column to ascertain that additional phase separation does not occur if the solutions are left standing.

The naphtha was subsequently evaporated from the unsaponifiable material to obtain a yield of 2.2 parts by weight of unsaponifiable material per 40 parts of original paste or a yield of 5.5 per cent based upon the original paste of soap subjected to treatment.

The crude unsaponifiable matter rich in sterols was dissolved in methanol in a ratio of about 1 part sterol to parts methanol and crystallized to yield 2.1 per cent of crude sterols based upon the tall oil soap concentrate. The sterols had a melting point of 118 to 120 C. Digitonin precipitation indicated a purity of 75.6 per cent. These sterols were further purified by decolorization with charcoal and crystallization from isopropanol to yield a fraction with a melting point of 119 to 122 C. Digitonin analysis indicated a sterol content of 82.1 per cent.

The mixture of soaps of rosin and fatty acids remaining in the water and alcohol from column I was subjected to evaporation to recover alcohol and naphtha which was returned to the process. The soaps were then acidified, washed and distilled at a pressure of about 1 mm. A light-yel low distillate suitable for use in the manufacture of alkyd resins, soaps and many other purposes was obtained. The pot residue in the still constituted only 7.8 per cent of the original paste solids. In contra-distinction in conventional procedure where tall oil is subjected to distillation in order to recover the acids thereof, the residue comprises 20 or 30 per cent of the tall oil.

The following additional examples illustrate the separation of the unsaponifiable matter from crude tall oil soaps of the type previously described employing varying ratios of tall oil in a water-isopropyl alcohol solution as a solvent. Separations were conducted at temperatures of 80 and 120 F. The extractions were conducted batchwise but the same principles are applicable to countercurrent extraction in an apparatus such as that disclosed in the drawing herein. In each instance the ratio of the immiscible or partly miscible solvent for unsaponifiable matter. e. g. naphtha of heptane grade was 1 to 1 with respect to the solution of crude tall oil soaps and unsaponifiable matter in water and alcohol.

Example II A crude mixture of tall oil soaps containing unsaponifiable matter was made up in water and isopropyl alcohol in a concentration of 17.6 per cent. The alcohol was varied over a range of 19 to 3'7 per cent in the water-alcohol-soap mixture. Clean separations of the naphtha from the soap solution in water and isopropyl alcohol were obtained over the entire range. The naphtha solution of unsaponifiable matter could be washed with water to free it of soaps and certain other constituents. The resultant mixture of unsaponifiable matter could be crystallized to obtain the sterols in relatively pure form. The alcohol may be recovered from the soaps by distillation and the fatty acids and rosin acids regenerated by acidification of the mixture. The acids could readily be fractionated by distillation methods.

Example III In this example the crude mixture of tall oil acid soaps and unsaponifiable matter was made up in Water and isopropyl alcohol in a concentration of 24 per cent. The isopropyl alcohol content of the solution to be extracted was varied within a range of 19 to 28.4 per cent. Extractions were conducted at F. and again at F. and satisfactory separation of the naphtha solution of unsaponifiable matter from the water and isopropyl alcohol solutions of soaps of rosin acids and fatty acids were obtained. The desired components of the two phases could be recovered in the manner previously described.

Example IV In this instance the crude mixture of tall oil acid soaps and unsaponifiable matter was made up to a concentration of 29.6 per cent in water and isopropyl alcohol. The isopropyl alcohol content of the soap mixture was varied over a range of 18 to 26 per cent. The extractions with naphtha were conducted at 80 F. and at 120 F. with good results.

Solutions of crude tall oil soaps when made up as herein described and extracted with a solvent for unsaponifiable matter countercurrently, are not subject to emulsification. Thorough and intimate contact of the alcoholic solutions with the solvent of unsaponifiable matter can be attained and quick and effective phase separation are still attained. Insofar as is known, these results have not heretofore been attained. With very high concentrations of both soap and isopropyl alcohol, the naphtha tends to become too miscible; therefore, with soap solutions of high concentration the isopropyl alcohol content should be reduced below the maximum attainable with solutions of hol-watcr; axes :and sides B i-C coiistitute zthez.

wateretall-oilisolids axes. r

:The graph an 1 Figure 1 2 'is'rbased upom extrac-r: tions' conducted at 86? The perceritaofattll =oil solids kcom'prising: alkali,..e.: g. sodium-:soapsof 5 rosin acids: and: fatty: i acidsf andiunsaporiifiaiblematter as previously described, may be as low as 5 or but usually for economies sake it is maintained .at a higher figure. The tall oil solids employed were a conventional .talloil. product from southern pine produced by the'.We'st Vir ginia Pulp & Paper Company andisoldunde'r the tradeiname ofTa11so.

The limbsLLandM are the approximate limits: of-op'erabilitylof the system. The area on .the' graph between limbs Land'lvl" include the: systems oi saponified tallloil solids, .water and alcohol which'are susceptibleof countercurrent extractionwithnaphtha; The portion of thevarea' below the branch Nembodies systems of, the three]. 20,

' the clear-mg,-zone a. The proportions; wererecomponents which at the temperature givenfare" regardedas being especially .suitableifo'r solvent extraction with'naphtha countercurrently. to. re-

moveunsap'onifiable matter from the soaps. In"

thisiarea, the naphtha andthe solution ofsoa'ps in water and 'isopropyl alcohol separate very" rap idly and completely into layers which can be drawn oiT from each other for recovery of the tall oil solids.

Figure 3 isasimilar graph illustrating.operable 1 systems, for countercurrent. extraction with naphtha of talloil solids in solution of water and isopropyl. alcohol at a temperature of 120 F. In i this curve, the. area embraced between the practicalsystems. of tall oil solids, water and iso-= propyl alcohol whichare susceptible ofcountercurrent extraction with naphtha in a column as illustrated in Figure 1 to obtain separation of the soaps. and the unsaponifiable matter. areabelow the branch Q. and between the latter branch and the branch P represent systems that are especially suitable for the application of the countercurrent technique because, in this area,

the-separation of the naphtha and the solution 43;

of tall-oilsolids in water and isopropyl alcohol is extremely rapid and complete and:the separation of the=unsaponifiable matter from the saponifi- :able matter isrelatively sharp.

t will be understood that any system falling within the areas :designated ins-Figures'2 and 3 is liquid at the temperature given, is but-'partially miscible :withmaphtha .anddoes-not form emulsions with the latter matter. The solutions can beeintroduced at-the. top-of an extraction zone such as-the zone or columnI of Figure 1 and'will flow countercurrently downwardly with-relatively completecormingling and contact with-upwardly flowing naphtha introchiced at the bottom; ofthe same zone. The naphtha solutionofrunsaponir. fiablermatter containing: small amounts of soaps of tall oil acidepasses-off from the clearing .zone b at the topof the column and can bereadily: washed-with water to remove .thesoaps-in the column II. Soapsolutions in water and'isopropyl alcoholare drawn off at the bottom from clearing zone a and can be processedgas'previously-idescribed.

-Ithas also :been indicated that theuprinciples of. the invention may" be applied to the use of; mixtures of water and .methanohor methyl al cohol: as solvent :IIldia=:fOI':'1'/8,11 oil solids in the countercurrent. extraction of unsaponifia'ble mat= ter of tall oil with-naphtha; The following--ex amplesillustrate this technique.

The in Example V rest gwasulmazinly sodiumr-soaps of tall oil; aoid s,- The composition;included-AQO,%. of; water= The saponified-.tall oil solids .-wer e made int o \a 2S01utioncomprising':;

% *tall oil solids 20% methanol water- The percentages as :given are bycweight, This solution-wast introduced-into the-inlet of, the {extraction {CO-11111111531. Naphtha; ewg; fraction ap; proximatelyheptane or, octane- 1 grade; and con.- sisting of .amixture-primarily of parafiinic hydro-,,. carbons containing 6- to.--101-carbon atoms ;-was; introduced at the bottom of the column but above spectively 45 parts by voluma-of-soaosolution; and 180 parts byvolume of naphtha, or a ratio of11 to 4.1, The-temperatureof the columnr-was 120 F.

The soap constituents-were drawnol? at -the lower; clearing zone-an ;in solution inthe water and-methanol and werezsubjficted to ;appr.opriate steps for recovery-of thettalLoil acids,- For-; ex;-, ample, thesolution was subjectedto acidificationr.

' with-sulphuric-acid or tl'iei lilrefltov precipitatega, mixtureiof: rosin acids and fatty acids. that could. be parated from thev water-methanol; layer andw dried. About 19.3 parts by weight-offtall'oil branchesOand P approximately includes the ."5 (mainlyacids) wasmec'overed Subsequently; if

desired;- the resin: acidscould be separated -iroz;nthefatty acids by appropriate ,technique; One convenient systemwould; involve distillation; preferably under 'relatively -highvacuum-.1 The:- fatty acids could also be selectively esterifiedavith,-; awlower; alcohol suchas methyl alcohol or ethyl alcohol and separated by: distillation-- or, other appropriate-technique:

The solutionzcomprisingz primarily unsaponi fiable -matter; including-sterols 'suchas; beta sitosteroL; higher,- alcohols (alcohols: containing; 22; carbon atoms or more-per molecule) a and otherconstituents, was taken. oft-in the naphtha: phaseattthe top..of "column I and :washed. with, ,water, to remove. any residual "soaps contained therein. Theawashinaoperation was performedin the manner prescribed, namely bypassing the naphtha. solution containing the unsap'onifiable materialito the bottom of column II and washingitwith water in the latter --column -in counterdrawnofi from the clearing zone at the top-oi column I II" and the urisaponifiable material wasrecovered preferably byevaporating thesolvent:

Theyield-of 'unsaponifiable matter was-3:78 parts--- by weight; Sterols were further concentrated by c5=c ystallizing them from an appropriate solvent;

such as a -solutlon of ethyl alcohol and acetone: In this manner-,-1.26i-parts:by-weightof the crude sterols of tall oil from norther mpir-iewere readilyrecovered to provide:a==product melting within-arange of. to. C. The-sterols-couldghavebeen further purified 'by appropriate technique; which it is not deemedto be necessary-further" to describe:

In similar manner, tall-oil-from southern-pine 75 was subjected to the-treatment of--this'invention-- in order to separate a concentration of unsaponifiable matter and to obtain the soaps of the fatty acids and rosin acids relatively free of unsaponifiable matter. It is to be understood that the tall oil of northern pine in many instances is highly rich in unsaponifiable matter and may contain 8 or 9% or perhaps even more of this material. It would also appear that the unsaponifiable matter from northern pine is relatively low in the long chain alcohols, such as -22 or higher alcohols, which are difficult to separate from tall oil sterols by conventional methods.

The following constitutes an example illustrating the application of the principles of the invention to the fractionation of the solid matter of southern pine tall oil.

Example VI The crude skimmings of the tall oil from southern pine were processed. These skimmings include about 60% of solid matter, the rest being essentially water. The skimmings were diluted to a composition of 20% methanol, 50% water and 30% tall oil solids in which the tall oil acids were present as sodium soaps. The solid matter readily Went into solution in the mixture ofwater and methanol to provide a solution which was readily susceptible of countercurrent extraction in the column I. To effect extraction of the solution, 45 parts by volume of the latter were introduced at inlet 3 of the column and 135 parts by volume of naphtha was passed in at inlet 4. The temperature of the system was 130 F.

The solution of soaps, rosin acids and fatty acids in water and methanol was drawn off from the clearing zone at the bottom of the column and the soaps were recovered. This could be accomplished by acidification of the soaps with sulphuric acid or the like to precipitate the free rosin acids and fatty acids. The acids were skimmed oil and Were then water washed to remove soluble impurities, such as sodium soaps and free acids. Residual solvents were evaporated from the tall oil acids. The product as recovered comprised 22.3 parts by Weight of crude tall oil material.

Rosin acids and fatty acids in this mixture could be recovered in a highly concentrated form by distillation.

The naphtha solution of unsaponifiable material from the southern tall oil was drawn ofi at the top of column I from the upper clearingzone and was then subjected to washing with 96 parts by volume of water in column II at a temperature of 105 F. Washed unsaponifiable matter in naphtha was drawn oil from the top of clearing zone of column II and 1.43 parts by weight of unsaponifiable matter was recovered by evaporation of the naphtha. It could be further purified, for example by crystallization by a solvent medium such as 6 parts ethyl alcohol and 4 of acetone at 0 C. At this temperature, a product comprising primarily the sterols of the tall oil having a melting point of 119 to 120 C. was recovered.

The formulation of systems of tall oil solid matter methanol and water suitable for countercurrent extraction with naphtha in the manner already described is illustrated in Figures 4 and 5 of the drawings. In these drawings, the various systems are graphed upon triangular coordinates in which the side 3-0 is the watermethanol axis, AB is the methanol-tall oil soap solids axis at the side A-C is the tall oil soap 10 solids-water axis. The area between the branches R and S ofthe curve in Fig. 4 and about the 10% soaps limit constitutes the zone in which liquid solutions of tall oil solids in water and methanol are obtained. These solutions can be extracted countercurrently with naphtha in the manner previously described into a naphtha phase con.- taining the unsaponifiable material and a watermethanol phase containing most of the soaps of rosin acids and fatty acids. The unsaponifiable material in naphtha can be drawn off from the clearing zone at the top of column I and the water-methanol phase containing the soaps can be drawn 011 from the lower clearing zone. The recovery of the various constituents can be conducted in accordance with the technique previously described.

It will be understood that other temperatures,

than those specified for the systems covered by the curves in Figures 2, 3, 4 and 5 may be employed in column I. The temperature range may, for example, extend from room tempera-,- ture or about F. up to F. and will include all of the intermediate temperatures.

Any solution falling between branches of the curve R S in Figure 4, or T and U of Figure 5 will be operative at the lower temperature specie fied, At other temperatures, certainvariations of the curvesof course will take place. It is impossible to illustrate all of the possible systems since the number of different temperatures is practically unlimited. Most of the systems contemplated by the present invention where methyl alcohol is employed as the alcoholic medium will be embraced by the formula:

Percent Tall oil solids 5 to 35 Methanol 12 to 65 Water 15 to'62 Of course, the operability of any particular system can be well determined by means of sample solutions which can be shaken up in bottled or other appropriate container with naphtha and left to stand for a short period of time. Operable solutions of soap and methyl alcohol must be liquid at the temperatures of extraction, must beat least but partially miscible with naphtha, must not form emulsions and must separate into phases when shaken, within a period of not morethan 6 minutes. Solutions that do not separate from naphtha within this period of time are unsuitable for counter-current extraction with naphtha in the manner above described. The better mixtures will separate usually within a period of 3 minutes or less. As already indicated, ethyl alcohol may also be substituted for isopropyl alcohol or methyl alcohol as the alcoholic component of the solvent of the soap mixture. solids content of the mixture will be within a range of 5 to 35% by weight. The alcohol will constitute 15 to 70% of the mixture.

- The forms of the invention herein described are to be considered as being merely by way of example. It will be apparent to those skilled in the art that numerous modifications may be made therein without departure from the spirit of the invention or the scope of the appendedclaims.

This application is a continuation-in-part of Where ethyl alcohol is so employed, the

:11 .=We. claim: ,.-1. A process .of obtaining the unsaponifiable rmatter ofitall oil in concentratedsform; which process comprisesmarkingup aisolut-ion of thetall toil soaps containing. :the. unsaponifiahle matter of-.-ta1l oil:from .thelm-anufacturerof paper pulp in a .concentrationaofi about; 5.-.to. 25 per .cent in isopropylalcohol and watenwith the finalsolution-containing fromc1-5lto 50v per cent of -=isopropyl alcohol and the remaindenxvatenandextracting out the unsaponifiable. matter. in. said solution by .countercurrently.fiowing .lthe solution iii-contact with-naphthain aratioofl-to. 2Qparts by-vo1ume per..part of tall-oil soap solution-at a temperature .of. 80 i to, .130. F,,rbyscontinuouslyintroducingthe solution into, aniupner portion of an extraction zone and continuous-lyintroducing naphtha into a ,lowenportionroi thesame zone, drawingioff theisolution .ofis.o.propyl alcohol and water .at theJower-end of .the zone at.,a.point below that of intro'diiotiom'of the. naphtha. and drawingoif the solution of unsaporiifiable matterin naphtha atlthe other end..'of thesystem at a point abovethat o'f-.intro'duction of thesolution and evaporating the naphtha from .the solution 'of'unsaponifiabie matter.

2. A1processbf. obtaining "the unsaponifiable matter bf tall: "oil in "concentratedform, "which processcomprises making up-a solution ofthe tall oilfronrthe manufacture of paper pulplina concentrationof 5 to 25,per cent inisopropy1"a1- c'oholand water .witlrthe" final solution-1 containingfrom" '15 to 50' percent "'of "isopropyl alcohol and'thememainder' water an'd extracting out the unsapoiiifiableun atter in's'aid Solution; "bycountercurrently fiowingthesbiu'tion in contactwith I5-to-10 parts by volume of naphtha per part of tallnoilrsoap solution at a .temperaturenofrriloxto BOQZRUby introducing the solution into an-rupper-portion of an extraction zone and naphtha into a lower portion ofthe zone, removing, a naphtha' s'oiution "of iunsap'onifia'ble 'matter' at the upper-en'd 'of the system at a'point abovethat of introduction 'of"thes'olution of the soaps at the other end of the system at" a point" below that 'ofintrdductiono'f the na'nl'itha; washing the naphthas'olution of unsaporiifiable' mattenwith water to remove" residual unsanonifiable" matter and evaporating "6d the naphtha.

' "3. i Inprocess-"of obtaining the' unsap'o'n'i'fiable matterb'f whole'tall-pil inconcentrated formfthe steps which comprise mak'ing" up 'a solution -"of whole: tall oil s'olids com rising rosin acid soaps and 'fatty atcid so'aps of-tall' oil'along with theunsaponifiablematter'of'tall:oil in=solution in water andiad'ower aicoh'olrot a. class consisting of methan'olzi ethan'cP- and isonropanoh the' concentration of SOfidSf b'ElIlE 5* ftO' 35-% ,'-rthe :percentage: of 'the alcohol for-methanol heingzin'a" range 'of 12-65% for-'ethanolabeing intaran'ge of 15:70 %'for risopropylsbeingrin a'.rangefof?15-50'%; ther'; extracting. the unsaponifiablerniatter" fIOIIISthET SOIUfiOII by'flowingthe solution continuous'ly into an elongated extraction-x zone :siiglitly below the"':top thereofi and-rintroducingznaphtha continuously l to a lower portion of theisame zoneZ'slightly above the rbottom. :thereof, ther-zone -being maintained within a rangerof 75.F. to 1-50F., allowing the solution-"and :naphtha:- to percolate countercurrently through eaehrzot-her'jin intimate contact, drawing oiT a solution of tall oil acid soapsin water .:-and =the alcoholat the bottom of the zone below ith'e point of inletcf naphtha and-then drawing the-solution of-unsaponifiable: matter in water at the top of the:zonexbetween".theinlet.

iii;

.from-the solution of originals in solids: from the water and alcohol and recoveringthe-solvents from the resultingsolution.

-.4: In a process of'obtaining the unsaponifiable matter of whole tall oil in concentrated-formpthe steps which comprise'making up a solution of 5 to"35% by weight of whole tall oil solids comprisingrosin acidsoaps and fatty acid soaps-of tall oil and the unsaponifiable matter of talloil in 15 to 62%by weight of water'and 12to- 65% by weight-of methanol,-thenextracting the unsaponifiablematter from the -solution by flowing the latter continuously into an elongated extraction'zone slightly bBlOWEthl-Z top thereofandtintroducing'naphtha continuouslyto the lower portion of the same zone, slightly above the bottom thereof, the zone being maintained within a range of F. to F., allowing the solution and naphtha to percolate countercurrently through each. other in intimate contact, drawing oiT a solution ofhtall oil acid soaps in waterand methanol atithe-bottom of the zone'belowlthe point of inlet of naphtha and drawing offa solution ofunsaponifiablematter and naphtha at the'top 'of'the zone and recoveringthe solvents from the resulting solutions.

5'.' In aprocess of obtaining the unsaponifiable matter of whole tall oil in concentrated form,.the steps which comprise dissolving-5 to 35% by weight of whole tall oil solids comprising rosin acid soaps and fatty acid. soaps of tall oil and the unsaponifiable matter of .tall oillin a mixture of water and allower alcohol .of the class consisting of methanol, ethanol and isopropanoLthe percentage ofthe.alcohol in the case. of ethanol being .in a.range ,of 15 itol'l0i%lby weight,.in.the case 'of. isopropanolbeing in a range ofsl5lto.'5(l% by: weight and in the case. ofrmethanol being .in arange. D112 ,to ,65% bylweight, then extracting the .unsaponifiablenmatter from the solutionby flowing the solution continuously .into an elongated extraction. zone. at l a point slightly spaced from thefirst extremity thereof and introducing a solventof unsaponifiable matter of a class consisting of diethyl ether, methyl ether, methyl ethyl ether, isopropyl ether, ethyl .isopropyl mixed ether, methyl 'isopropyl mixed ether, benzene, toluene, xylene, naphtha and ethylene dichloride in a .proportionof 1 volume-to 20 volumes per volume of soap solution, the solventbeingintroduced continuouslyinto, a portion of thelextraction zone. slightly spaced .from the .second extremity thereoflthe zone being maintained within a range of 75 F. to 150-F., allowing the solutionand sol-vent I to .percolate countercurrently through each other inintimate contact, drawing off a solution of tall oil acid soaps in water and the alcohol at the second mentioned extremity of the zone,-then drawing off thesolution of unsaponifiable matter in the solvent'thereofat the first mentioned extremity of the zone and recovering .the solvents ,from the resultant solutions.

--6. In a process of obtainingthe unsaponifiable matter of whole tall oil in concentrated form,'the steps which comprise dissolving whole tall oil solids comprising rosin acidtsoaps and fatty acid soapsrof tall oil and theunsaponifia'blematter of-tallsoilin'a mixture of water and anlower alkyl monohydric alcohol-containing from 1 .to 3- carbon atoms permolecule-to form a'solution which comprises 5.to=35%of said solids, 15 to 50% said lower alcohol and dearest of the composition being-water, then extracting {the zunsaponifiable matter .1 from the :solution' ,byifiowing the 1 solution continuously into an elongated extraction zone at a point slightly spaced from the first extremity thereof} and introducing-ansolvent of unsaponifiable matter of a class "consisting of diethyl ether, methyl ethyl ether, isopropyl ether, ethyl isopropyl mixed ether, methylisopropyl mixed ether, naphtha, benzene, toluene, xylene and ethylene dichloride in a proportion of 1 volume to 20 volumes per volume of soap solution, the solvent being introduced continuously into a portion of the extraction zone slightly spaced from the second extremity thereof, the zone being maintained at a temperature within a range of 75 F. to 150 F., allowing the solution and the solvent to percolate countercurrently through each other in intimate con'tactfdrawing off a solution of tall oil acid soaps in water and the lower alcohol at the second extremity of the zone, then drawing ofi the solution of unsaponifiable matter in the solvent thereof at the first mentioned extremity of the zone and recovering the sol vents from the resultant solutions.

ROGER M. CHRISTENSON. STEWART W. GLOYER.

REFERENCES CITED ihe following references are of record in the file of this patent:

UNITED STATES PATENTS OTHER REFERENCES Book of Standards, A. S. T. M., 1944, part III. 

